Tiny House Building for Chemical & Mold Sensitive Person
My Son-in-law is building a tiny house for me.
I am really concerned about the insulation to use and putting vents in the eves or not, I’ve not seen people doing this on any of the build videos and I don’t know why, my SIL wants to put in vents. There will not be attic space.
It is normal house construction with the the greenest materials I can afford on my limited budget.
It will be a gable roof, no fancy buildouts in the roof just a straight gable, loft for company to sleep in and open over the living room. We are going to use a metal roof.
I want the home to breathe, not trap moisture, not off gass and there won’t be an HVAC system, just opening windows for natural ventilation, space heater or using a wood stove when its super cold. I typically like my home to be about 60 degrees, I’d rather put on a sweater than crank up the heat. In the hot months, typically just August here in Oregon, a window ac unit will suffice. There will be major vents in the shower and in the kitchen to remove moisture so we shouldn’t have a mold issue.
It will be 8’x24′.
Any advice, anyone can give us is greatly appreciated.
Thanks,
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Replies
Victoria,
Whether or not you have vents in your soffits depends on whether you want a vented insulated roof assembly or an unvented insulated roof assembly.
To learn about the difference, and to decide which one you want, see this article: How to Build an Insulated Cathedral Ceiling.
I'm a bit surprised that someone with chemical & mold sensitivites tolerates heating with a woodstove, but I s'pose those are different chemicals, eh? Cordwood carries a TON of mold spores with it too, but they'll only survive/thrive if you allow the interior relative humidity to exceed 60% RH @ 70F. In your climate it's not tough to control the interior RH to under 50% by the ventilation rate (open a window or run an exhaust fan), since the outdoor dew points are usually pretty low.
In most of OR (all except highest altitude locations) you can heat and cool tiny houses with a ductless mini-split heat pump quite efficiently, and while they don't come with great air filters, unlike cord wood it doesn't innoculate your house with a new batch of fungi & mold every time you need to run it. They can also be run in "dehumidify" mode, any time you need to bring the relative humidity down quickly. (But with all but the Daikin Quaternity series, dehumidifying will always be accompanied by cooling off the air somewhat too.)
If you're not sensitive to newspaper inks, insulating with cellulose incorporates borates which function as both a mold/fungicide & fire retardent, but it's made of shredded newspaper.